Steam for Androids & iphones
Surprised not to have found a thread about this already, so here you have it.
Its in beta at the moment, I've installed the app already on my Android but what with being a beta and "steam working" I haven't got it up and running but,,, have a friend that has, which is a good thing.
So try your luck and see what happens...
Seems handy for the chat if nothing else. The rest kind of need fleshing out, but it's still in beta, so time will fix these things (in theory).